Question about rand and srand

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  1. #1
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    Question about rand and srand

    Greetings!

    I am new to C++ and I am currently reading jumping into C++ featured on this website. I am reading about the rand and srand functions. The book claims you need a function prototype for these functions however when i input the prototypes my compiler gives me an error untill i comment out the prototypes. Is this expected and if so why? I have copied my code below to give an example with the offending code commented out.

    Thank you for your help!

    Code:
    #include <iostream>
    #include <cstdlib>
    #include <ctime>
    using namespace std;
    
    int main()
    {
    
    //void srand(int x);//function prototype to generate random seed.
    //int rand; // function prototype for random number generation.
    
    int random_seed = time( NULL ); // set random seed based on unix clock
    srand(random_seed);
    cout << rand() << "\n";
    cout << rand() << "\n";
    cout << rand() << "\n";
    cout << rand() << "\n";
    }

  2. #2
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    The declarations (aka function prototypes) for rand() and srand() are in <cstdlib>.

    The declarations you have commented out are in conflict with the declarations in <cstdlib>, hence the compilation errors.
    Right 98% of the time, and don't care about the other 3%.

    If I seem grumpy or unhelpful in reply to you, or tell you you need to demonstrate more effort before you can expect help, it is likely you deserve it. Suck it up, Sunshine, and read this, this, and this before posting again.

  3. #3
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    Quote Originally Posted by grumpy View Post
    The declarations (aka function prototypes) for rand() and srand() are in <cstdlib>.

    The declarations you have commented out are in conflict with the declarations in <cstdlib>, hence the compilation errors.
    grumpy,

    Thank you for your time. That makes perfect sense!

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